Compressor.



EDMUND W. ROBERTS, OF CLYDE, OHIO.

COMPRESSOR.

Specification of Letters Patent.

Patented March 31, 1908.

Application led September 29, 1906. Serial No. 336,755.

' To all whomit may concern:

Be it known that I, EDMUND W. ROBERTS, a citizen of the United States, residing at Clyde, in the county of Sandusky and State of Ohio, have invented certain new and useful Improvements in Compressors; and I do hereby declare the following to be a full,

clear, and exact description of the same,`

such as will enable others skilled in the art to which it appertains to make and use the same.l

My invention relates to air and gas compressors, and particularly to multi-stage compressors, and comprises novel arrangements of the low pressure and high pressure cylinders and pistons, intercooler, water jacket, and valves, as hereinafter more fully described andparticularly pointed out in the claims.

, ing of the low pressure disc The objects of my invention are to im'- prove and simplify air and gas compressors, to adapt the same to run at high speeds while compressing to high pressures, to improve the arrangement of compression cylinders and intercooler and the means for cooling these parts, to improve the valves of such compressors, and generally to produce a simple and compact compressor, small in pro' portion to its ca acity, capable of direct connection to a hig speed motor and of operating at`the speed of such motor, possessing few parts, and free from iliability to derangement.

I will now proceed to describe my invention with reference to the accompanying drawing, showing one form ofcompresso'r embodying my invention, and will then point out the novel features in claims.

In the said drawing: Figure 1 shows a central vertical section of my improved compressor, and of the cylinder and piston and crank case of a driving motor therefor, the

motor shown being a high speed two cycle explosion engine. Fig. 2 shows a vertical section through the water jacket, intercooler, and low pressure discharge valve on the line :1c-x of Fig. 1. Fig. 3 shows a horizontal section through the water jacket, intercooler, high pressure cylinder and piston and housiarge valve, said section taken on the line y--y of Fig. 1. Fig. 4 shows -a central vertical section of the low pressure discharge valve, housing, and associated parts. Fig. 5 shows a central vertical section of the compression cylinders andassociated arts (the pistons omitted) on a lar er sca e than Fig. 1.

he machine shown in Fig. 1 comprises a.

compressor 1 and ex losion motor 2, having in common a crank s aft 3, an englne bed 4,

and fly-wheel 5. The explosion motor 24 comprises a water jacketed working cylinder 6, piston 7, connecting rod 8, closed crank case 9 and electric igniter 10-all these parts constructed and arranged as customary in the best type of high speed two cycle explosion engine ractice; and since I claim no novelty, in t is a plication, for any feature of construction of said explosion motor, nor do I limit -mysellto this or any particular type of motor for driving the compressor, I do not conceive that it is necessary to refer further to said motor, except to say that a motor such as shown' is Well adapted to Work at speedsof from 600 to 1200 revolutions per minute and over.

The compressor shown is a two stagecompresser, comprising a low pressure cylinder 11, a high pressure cylinder 12, and low pressure and high pressure pistons 13 and 14 respectively, said pistons, being differential pistons connected as shown and having a common wrist pin 15 and-connecting rod 16, the compression space of cylinder 11 bein the annular space surrounding the lower end of the high ressure iston 14, andvbounded by the hea and si es of the low pressure cylinder 11 and the head of the low pressure piston 13. y

Low pressure piston 13 serves as its own admission valve, the cylinder 11 having a plurality of admission ports 17 arranged to e uncovered by the plston near the lower end of its stroke, air then rushing in through these ports 17 to fill the low pressure cylinder. A screen 18 (see particularly Figs. 2 and 5) surrounds cylinder 11 and covers these ports 17, and serves to revent the entry of large objects which' inlght foul or interfere with the operation of the compressor, and also to muffle the suction. B avoiding tlie-use of, admission valves, suoli as are commonly used on compressors, I

'avoid altogether the noisy clashin and chattering of such valves against tieir seats, which is one disagreeable feature of ordinary vair compressors.

For eflicient operation of two-stage compressors, it is necessary that the air compressed by the low pressure cylinder shall V30 housing 23.

be cooled before it is admitted to the high pressure cylinder; the cooling device for this pur ose being commonly termed an intercoo er. It is also necessary for effective 5 o eration of the compressor at high speed, t at there shall be considerable storage space between the low pressure and high pressure cylinders. The intercooler I employ (which intercooler likewise provides necessary storage or receiving space intermediate the cylinders) comprises a hollow casting 19 of horseshoe shape, supported upon the head of the low pressure cylinder and surrounding the high pressure cylinder 12. The low pressure cylinder has at its upper end a discharge port 20, with which an orifice 21 (Fig. 4,) on the lower side of the intercooler, registers; and between the head of the low pressure cylinder and intercooler there is a removable valve seat 22 having a similar registering orice. Within the intercooler is a cylindrical valve housing 23, integral with the valve seat 22, and having ports 24 at its sides, leading to the interior of l25 the intercooler; and within said housing is a hollow valve plug 25 seating against the valve seat 22, and provided with a spring' 26, the pressure of which may be regulated by a screw plug 27 screwing into the top of valve Whenever, during the up stroke of the low pressure piston 13, the pressure in low pressure cylinder 11 exceeds the pressure holding said valve closed, said valve will o en, admitting air from the low ressure cy inder into the intercooler 19. aid valve 25 closes automatically when the piston 16 ceases to ascend.

For cooling the upper end of the low pressure cylinder, the high pressure cylinder, and the intercooler 19, I provide a single water jacket 28 surroundin all these parts. By em loying a single jaclgiet for the purose, avoid an unnecessary number of jackets, pipes, joints, etc. Since the water circulates around both sides of the intercooler and completely around the high pressure cylinder as well as around that portion of the low pressure cylinder in which any considerable heat is generated the radiated surface in contact with the water is very lar e in proportion to the size of the parts an the volume of the water jacket. Except for convenience in manufacture and assembling, the intercooler 19 might be a chamber completely encircling the high pressure cylinder and formed integrally with the low pressure and high pressure cylinders. I have found in practice that it is very difficult to obtain perfect castings when forming the low pressure and high pressure cylinders, and

annular intercooler, in one casting; and it is inconvenient to assemble and connect with the low ressure and high pressure cylinders, an annular intercooler completely surrounding the high pressure cylinder. But by making the intercooler annular, but of horseshoe shape, the gap 29 between the horns of the horseshoe being wider than the external diameter of high pressure cylinder 12, it, is easy to put the intercooler in place or to remove the same, the water jacket'iavin first been removed. n One important feature of my invention resides in the means of securing the water jacket to the single casting comprising the low pressure and high pressure cylinders. As shownparticularly in Figs. 1, 2 and 5, thev high pressure cylinder has at its top a wide flange 30, and the waterljaeketlwhich at its lower end forms a joint with ange 31 of 80 the low pressure cylinder, has a flange 32 it- .ting over flange 30 of the high pressure cylinder, and bolts 33 screwing into flangeQ holds the water jacket in place the single set"" of bolts 33 constituting one set ofdattaching 85 devices, roducing the pressure necessar\y\to-\ close'bot jacketjoints.e.,thejoints at both iianges, 30 and 31.

Another' important feature of my invention resides in the means for securing the intercooler to the cylinder casing. For securing the intercooler to the head of the low pressure cylinder I employ bolts 45 passing Y through ianges of the cylinder head and of the intercooler, as shown in Fig. 2. A horizontal screw 34 (Figs. 1 and. 5) passing through the intercooler into the high pressure portion of the main cylinder casting, secures the intercooler to said cylindercasting. This screw v34y has in it a central passage 35 connected by ports 36 with the interior of the intercooler, and leading to the high-pressure admission valve 37, which is a spring-actuated valve, as shown, having a port 38 leading to the upper end of the high-pressure cylinder. Said high-pressure cylinder has a spring-actuated dischargelvalve set into its head, and comprising a valve housing 39 screwing into the' end of the high pressure cylinder, cuppedvalve plug 40, bushing 41 surrounding the housing 39 and provided with' an outlet screw threaded for the attachment of a delivery pipe, screw-threaded head 42, and spring 43. Valve plugs 25 and 40 are made hollow, as shown, in order that they may be as light as possible. I find that at the high speed at which this com ressor runs, unless lthese valves be exceeding y light they will hammer the seats to such extent as to seriously deform the same. By making the valves hollow as shown, however, the inertia of the valves becomes so small that no deformation either of the valves or of their seats results. It will be seen that the construction of the discharge valve described is such that when the screw head 42 is unscrewed somewhat, the bushing 41., forming the exterior valve chamber, may be turned to any desired position, thus permittin the compressor to deliver in any desired ireccap and said bushing and between said bushing and the head of the cylinder.

find that the speed at which the compressor works is materially affected by the type of valves employed. I find that housed check valves for the discharge valves of the low-stage cylinder 11 and high-stage cylinder 12, having cupped valve plugs, such as and 40 shown, and, for an admission valve to the hi h-stage cylinder, an open check valve, suc as 37, shown', give the best results and permit a materially higher speed of operation than if a different arran ement of valves be employed. This is dou tless because the housed valves are very quick in opening and the valve plugs may be made very light, while the open check valve is very quick 1n closing. A removable screw-plug 44 affords access to valve 37.

As indicated, suitable packing material is provided between the water jacket 28 and the c linder flanges upon which; it sets, and also etween the valve sjeat 22 and the adjacent parts,-between the screw 34 and the adjacent parts, and between the lhead of v the high pressure cylinder and its discharge valve. l

This compressor as shown, is designed to work at speeds in excess of 500 revolutions per minute and to compress to (pressures ofv 400 pounds per square inch an over. By giving the compression cylinders different proportions I may of course, adapt the compressor to compress to either higher or lower pressures efficiently. Relativel high speed of this compressor is permissib e, and relatively high compression pressure is obtainable, because of the design of the compression cylinders, pistons, connecting rods, etc., which in form, construction and proportions approximate ycorresponding parts of hi h speed explosion engines, and ecause of t e very small clearance of the cylinders, the relatively large storage capacity afforded by the annular intercooler, and the quick action of the automatic valves employed.

.What 1 claim is 1. A multi-stage compressor comprising in combination compression cylinders of different stages,.and an intercooler com rising yGO la hollow annulus connected tol bot said cylinders and surrounding one of them.

2. A multi-stage compressor comprising in combination compression cylinders of different stages,`and an intercooler yconnectedy to both said cylinders and surrounding one of them and having the form of a hollow annulus, there being space for the circulation of cooling fluid on both sides of such annulus.

y 3. A multi-stage compressor comprisin in combination compression cylinders ofdi erent stages, and an intercooler comprising a n' y a hollow annulus connected to both said cylinders and arranged substantially concentrically with respect to one of them.

4. A multi-,stage compressor comprisinr in combination compression cylinders of di erent stages andan intercooler vremovably connected to both said cylinders and having the form of a hollow horseshoe, the gap between its horns adapted to permit lateral removal of said intercooler.

5. A multi-stage compressor comprising in combination compression cylinders of different sta es, an intercooler comprising a hollow annu us connected to both said cylinders and surrounding one of them, and a jacket surrounding both said cylinders and said intercooler and adapted to contain cooling uid.

6. A multi-stage compressor comprising in combinationA compression cylinders of different stages, an intercooler comprising a hollow annulus connected to both said cylinders, and a jacket surrounding both said cylinders and said intercooler and adapted to contain cooling fluid; said chamber located entirely within said jacket.

7. A multi-stage compressor comprising in combination compression cylinders of different stages arranged in tandem, an intercooler constituting the receiver between said cylinders connected to both said cylinders and surrounding the higher-stage cylinder, and a jacket surrounding both said cylinders and said intercooler and .ada ted to contain cooling fluid; said .intercooler ocated entirely within said jacket.

8. A multi-stage compressor -comprising in combination compression cylinders of different stages and of different diameters arranged in tandem, an intercooler constituting the receiver between said cylinders connected to both said cylinders and surrounding the one of smallerdiameter, and a 'acket surrounding both said cylinders an said intercooler and adapted to contain cooling fluid said intercooler located entirely within said jacket. I

9. A multi-stage compressor comprising in combination compression cylinders of different stages and of different diameters arranged in tandem, an intercooler connected to both said cylinders and surrounding the one of smaller diameter, said intercooler having the form of a hollow horseshoe, the gap between its horns ermitting lateral removal of said intercoo er from the cylinder surrounded by it.

10. A multi-stage' compressor comprising in `combination low-stage and high-stage cylinders comprised in a single structure, a jacket surrounding said cylinder structure and ada ted to contain cooling fluid, and an intercoo fir-within said jacket ,said intercooler constitut ng the receiver between said cylinders and provided at one side with valved means directly connecting said intercooler with the low stage cylinder, and provided at the other end with valved means directly connecting said intercooler with the high stage cylinder.

11. A multi-stage compressor comprising in combination low-stage and high-stage cylinders of different diameters com rised 1n a single structure, a jacket surroun ing said cylinder structure and adapted to contain cooling fluid, and an intercooler within said jacket and surrounding the cylinder of smaller diameter, said intercooler constituting the receiver between said cylinders and provided at oneside with valved means directly connecting said intercooler with the low stage cylinder, and provided at the other end with valved means directly connecting 'said intercooler with the high stage cylinder.

12. A multi-stage compressor comprising in combination cylinders of different diameters comprised in a single structure, a laterally removable intercooler surrounding the smaller cylinder and having the form of a hollow horseshoe, the ap between its horns permitting its latera removal, and a lon itudinally-removable jacket surroundin intercooler and the cylinder surrounde by it, and adapted to contain cooling fluid.

13. A multi-stage compressor comprising in combination low-stage and high-stage cylinders, an intercooler surrounding one of them and laterally removable with respect thereto, said intercooler connected to the low-stage cylinder, and fastening means securing said intercooler to the high-stage cylinder having within it a passage connecting the interior of said intercooleriwith said highstage cylinder. r

' 14. A multi-stage compressor comprising in combination low-stage and high-stage cylinders, and an intercooler surrounding one of l them and laterally removable with respect thereto, said'intercooler provided with means 4mechanically securing it to such cylinder and comprising a fastening piece having within it a passage connecting the interior of such intercooler with such cylinder; said intercooler also connected to the other cylinder.

15. A multi-stage compressor comprising in combination low-stage and high-stage cylinders, an intercooler surrounding one of them and laterally removable with respect thereto, and a fastening member for securing said intercooler to that cylinder which it surrounds, passing through the intercooler and secured to the wall of such cylinder and having within it a passage connecting the interior of the intercooler with the high-stage cylinder; said intercooler also connected to the low-stage cylinder.

16. A multi-stage compressor comprising in combination, low-stage and high-stage cylinders, an intercooler surrounding one of them and laterally removable with respect cylinder, and a fastenin thereto, said intercooler connected to the low-stage cylinder, a discharge valve for such low-stage cylinder located Within the intercooler, an admission valve for the high-stage memberl securing said intercooler to the cy inder which it surrounds an'd havin within it a passage leading from the interior of the intercooler to the said admission valve of the high-stage cylinder.

17. A multi-stage compressor comprising in combination, low-stage and high-stage cylinders, an intercooler connected to both cylinders, a housed check valve between the low-stage cylinder and said intercooler, an open check valve between the intercooler and the high-stage cylinder, and a housed discharge valve for the high-stage cylinder.

18. A compressor com rising in combination, a compression cy inder, a receiving chamber, a valve housing therein having a flange and a valve seat, means for securing said housing and cylinder together, and a valve within said housing.

19. A compressor comprising in combination, a compression cy inder, a receiving chamber, a valve housing therein having a flangey and a valve seat, means for securing said housing and cylinder together, a valve within said housing, a spring therefor also within saidhousing, and a screw closure for the end f the housing.

20. A multi-stage compressor comprising in combination, compression cyhnders, an

intercooler connected to both, a valve housing for the discharge valve of one of said cylinders located within the intercooler and havin a flange and the valve seat, a valve in such housing, and means for securing said housing and the corresponding cylinder together.

21. A multi-stage compressor comprising in combination, low-sta e and high-stage cylinders and an intercoo er therefor, and a single jacket surrounding the high stage cylinder, the intercooler, and the compression space of the low-stage cylinder, said latter cylinder provided with an admission port outside the jacket.

22. A multi-stage compressor comprising in combination, high-stage and low-stage cylinders arranged in tandem, an intercooler therefor, and a single jacket surrounding the high-stage cylinder, the intercooler and the upper portion of the low-stage cylinder, said latter -cylinder having an admission port beneath the jacket.

23. A compressor comprising in combination, a cylinder structure having lateralflanges, a receiving chamber between said flanges, and a jacket surrounding said cylinder structure and receiving chamber, and seating upon said flanges.

24. A compressor comprising in combination, a cylinder structure having lateral anges, a receiving chamber` between said flanges, a jacket surrounding 'said,cylinder structure and receivin cham er, and seating upon said flanges, an a single set of fastenn devices pressing said lacket toward and ho ding it against both sai flanges.

25. A compressor comprising in combination, a com ression cylinder and a discharge valve there or comprising a housing secured to said c linder, a valve Within said housing, a rotatable bushing surrounding said housing, and provided with means adapting it for connection to a discharge conduit, and

means closing the end of sald bushing and the end of said housing and holding said' bushing in place.

26.A A compressor comprising in combination, a ,com ression cylinder and a discharge valve there or comprising a housing secured thereto, a valve Within said housing, a rotatable bushin surrounding said housing, and

. provided Wit means adapting it for connection to a discharge conduit, and a screw cap closin the end of said bushing and the end o sai housing and holding said bushing in ace.

27. In a multi-stage complrlessor, the combination of low-stage and 'gh-stage cylinders arranged in tandem an annular intercooler surrounding said high-stage cylinder and connected to both cylinders, and suitable 'valves comprising an admission valve for the' high-stage cylinder, said admission valve being an open check valve located in a passage connecting the intercooler and said high-stage cylinder, said passa e having an extension leading through the ead of such cylinder t0 the outside, and a plug normally c osing such extension but ada ted upon removal to afford access to said va ve plug.

In testimony whereof I afiix my signature, in the presence of two Witnesses.

m EDMUND W. ROBERTS. Witnesses:

H. M. MARBLE, MAY I. TRIMBLE. 

